The present disclosure relates to sealing of a quartz tube containing an electrical device with an electrical lead extending from the tube through the metal wall of a pressurized fluid vessel. Such tubes are employed in fluid purification systems utilizing radiation, such as that emanating from an ultraviolet lamp, within the quartz tube for purification of the fluid. Purification systems employing UV radiation are used in commercial fluid filtration and purification systems where the fluid is to be recycled or used continuously in a process and particularly for water filtration and purification processes.
In systems of the aforesaid type, the pressure vessel may have a removable lid with a plurality of quartz tubes extending therethrough and sealed therein for providing within each of the tubes an ultraviolet lamp for irradiating the fluid in the pressure vessel. In applications where the pressure vessel is of a relatively large volume with a multiplicity of quartz tubes provided through the lid, each with a UV lamp therein, the pressure vessel may be operated with fluid pressures therein in the order of 10 bar (1013 kPa) with fluid temperatures ranging from −60° C. to 105° C. It will be understood that when it is required to remove the lid from the pressure vessel for servicing the contents of the pressure vessel, which may include filters, that it is first required to remove the quartz tubes and UV lamps before the lid is removed from the pressure vessel. Also, it is desirable that the quartz tubes may be removed individually for UV lamp replacement without removing the lid. In such pressure and temperature environments, it has been found difficult to provide a simple, reliably sealing arrangement for sealing the quartz tube in the lid of such a pressure vessel in a manner which provides for easy removal and reassembly. Providing a simple, reliable, readily installable and easily removable technique for sealing of the quartz tube through the metal lid of the pressure vessel has proven difficult in view of the brittleness of the quartz tube with respect to providing the necessary sealing to retain the fluid pressure in the vessel and preventing leakage between the quartz tube and the metal lid. In addition. In the event of breakage of a quartz tube, it is required to maintain the integrity of fluid sealing to prevent fluid escape from the vessel, either around the quartz tube or around the electrical cable. This has proven particularly difficult and complex where extremes of fluid temperatures are encountered. In addition, the electrical leads for the UV lamp extending from the quartz tube require additional securing and flexure strain relief to prevent damage and/or shorting of the electrical leads. Heretofore, this has required a multiplicity of fittings and seals to accomplish the intended result. Thus, it has been desired to provide a simple easily installed and removed and effective way of sealing a quartz tube through the metal wall of a pressure vessel and to provide for securing and strain/flexure relief of the electrical leads extending from the quartz tube.